Pulmonary embolism with clot in transit: An analysis of risk factors and outcomes

Heart lung axis in acute pulmonary embolism: Role of CT in risk stratification

Pulmonary embolism (PE) remains a significant cause of mortality requiring prompt diagnosis and risk stratification. This review focuses on the role of computed tomography (CT) in the risk stratification of acute PE, highlighting its impact on patient management. We will explore basic pathophysiology of pulmonary embolism (PE) and review current guidelines, which will help radiologists interpret images within a broader clinical context. This review covers key CT findings which can be used for risk stratification including indicators of right ventricular (RV) dysfunction, clot burden, clot location and left atrial volume. We will discuss the measurement of RV/LV diameter ratio as a key indicator of RV dysfunction and its limitations and challenges within various patient populations. While these parameters should be included in a radiologist's report, their predictive value for mortality depends on the patient's existing cardiopulmonary reserve and should not be interpreted in isolation.

International Clinical Practice Guideline Recommendations for Acute Pulmonary Embolism: Harmony, Dissonance, and Silence

Despite abundant clinical innovation and burgeoning scientific investigation, pulmonary embolism (PE) has continued to pose a diagnostic and management challenge worldwide. Aging populations, patients living with a mounting number of chronic medical conditions, particularly cancer, and increasingly prevalent health care disparities herald a growing burden of PE. In the meantime, navigating expanding strategies for immediate and long-term anticoagulation, as well as advanced therapies, including catheter-based interventions for patients with more severe PE, has become progressively daunting. Accordingly, clinicians frequently turn to evidence-based clinical practice guidelines for diagnostic and management recommendations. However, numerous international guidelines, heterogeneity in recommendations, as well as areas of uncertainty or omission may leave the readers and clinicians without a clear management pathway. In this review of international PE guidelines, we highlight key areas of consistency, difference, and lack of recommendations (silence) with an emphasis on critical clinical and research needs.

Intermediate-Risk and High-Risk Pulmonary Embolism: Recognition and Management: Cardiology Clinics: Cardiac Emergencies

Pulmonary embolism (PE) is the third most common cause of cardiovascular death. Every specialty of medical practitioner will encounter PE in their patients, and should be prepared to employ contemporary strategies for diagnosis and initial risk-stratification. Treatment of PE is based on risk-stratification, with anticoagulation for all patients, and advanced modalities including systemic thrombolysis, catheter-directed therapies, and mechanical circulatory supports utilized in a manner paralleling PE severity and clinical context.

Right Ventricular Recovery: Early and Late Changes after Acute PE Diagnosis

Right ventricular (RV) failure is a critical cause of morbidity and mortality in patients presenting with pulmonary embolism (PE). The presentation of RV failure is based on the combination of clinical findings, laboratory abnormalities, and imaging evidence. An improved understanding of the pathophysiology of RV dysfunction following PE has given rise to more accurate risk stratification and broader therapeutic approaches. A subset of patients with PE develop chronic RV dysfunction with or without pulmonary hypertension. In this review, we focus on the impact of PE on the RV and its implications for risk stratification, prognosis, acute management, and long-term therapy.

What echocardiographic findings differentiate acute pulmonary embolism and chronic pulmonary hypertension?

BACKGROUND

Pulmonary embolism (PE) and pulmonary hypertension (PH) are potentially fatal disease states. Early diagnosis and goal-directed management improve outcomes and survival. Both conditions share several echocardiographic findings of right ventricular dysfunction. This can inadvertently lead to incorrect diagnosis, inappropriate and potentially harmful management, and delay in time-sensitive therapies. Fortunately, bedside echocardiography imparts a few critical distinctions.

OBJECTIVE

This narrative review describes eight physiologically interdependent echocardiographic parameters that help distinguish acute PE and chronic PH. The manuscript details each finding along with associated pathophysiology and summarization of the literature evaluating diagnostic utility. This guide then provides pearls and pitfalls with high-quality media for the bedside evaluation.

DISCUSSION

The echocardiographic parameters suggesting acute or chronic right ventricular dysfunction (best used in combination) are: 1. Right heart thrombus (acute PE) 2. Right ventricular free wall thickness (acute ≤ 5 mm, chronic > 5 mm) 3. Tricuspid regurgitation pressure gradient (acute ≤ 46 mmHg, chronic > 46 mmHg, corresponding to tricuspid regurgitation maximal velocity ≤ 3.4 m/sec and > 3.4 m/sec, respectively) 4. Pulmonary artery acceleration time (acute ≤ 60-80 msec, chronic < 105 msec) 5. 60/60 sign (acute) 6. Pulmonary artery early-systolic notching (proximally-located, higher-risk PE) 7. McConnell's sign (acute) 8. Right atrial enlargement (equal to left atrial size suggests acute, greater than left atrial size suggests chronic).

CONCLUSIONS

Emergency physicians must appreciate the echocardiographic findings and associated pathophysiology that help distinguish acute and chronic right ventricular dysfunction. In the proper clinical context, these findings can point towards PE or PH, thereby leading to earlier goal-directed management.

Clot-in-transit: A ticking time bomb in the heart with serious consequences

Clot-in-transit is associated with severe pulmonary embolism and higher mortality than acute pulmonary embolism without clot-in-transit. The optimal treatment of clot-in-transit is not established. Multiple treatment options have been described, including anticoagulation alone, systemic thrombolysis, surgical embolectomy and endovascular catheter-based therapies. Clot-in-transit can embolize to the pulmonary circulation in a matter of seconds and be immediately fatal. We describe two cases of clot-in-transit which embolized quickly upon Intensivist's evaluation and were associated with serious consequences. Management decisions for clot-in-transit should be emergent and based on multidisciplinary discussion of the pulmonary embolism response team.

Evaluating cardiopulmonary function following acute pulmonary embolism

INTRODUCTION

Pulmonary embolism is a common cause of cardiopulmonary mortality and morbidity worldwide. Survivors of acute pulmonary embolism may experience dyspnea, report reduced exercise capacity, or develop overt pulmonary hypertension. Clinicians must be alert for these phenomena and appreciate the modalities and investigations available for evaluation.

AREAS COVERED

In this review, the current understanding of available contemporary imaging and physiologic modalities is discussed, based on available literature and professional society guidelines. The purpose of the review is to provide clinicians with an overview of these modalities, their strengths and disadvantages, and how and when these investigations can support the clinical work-up of patients post-pulmonary embolism.

EXPERT OPINION

Echocardiography is a first test in symptomatic patients post-pulmonary embolism, with ventilation/perfusion scanning vital to determination of whether there is chronic residual emboli. The role of computed tomography and magnetic resonance in assessing the pulmonary arterial tree in post-pulmonary embolism patients is evolving. Functional testing, in particular cardiopulmonary exercise testing, is emerging as an important modality to quantify and determine cause of functional limitation. It is possible that future investigations of the post-pulmonary embolism recovery period will better inform treatment decisions for acute pulmonary embolism patients.

A clinical decision framework to guide the outpatient treatment of emergency department patients diagnosed with acute pulmonary embolism or deep vein thrombosis: Results from a multidisciplinary consensus panel

The outpatient treatment of select emergency department patients with acute pulmonary embolism (PE) or deep vein thrombosis (DVT) has been shown to be safe, cost effective and associated with high patient satisfaction. Despite this, outpatient PE and DVT treatment remains uncommon. To address this, the American College of Emergency Physicians assembled a multidisciplinary team of content experts to provide evidence-based recommendations and practical advice to help clinicians safely treat patients with low-risk PE and DVT without hospitalization. The emergency clinician must stratify the patient's risk of clinical decompensation due to their PE or DVT as well as their risk of bleeding due to anticoagulation. The clinician must also select and start an anticoagulant and ensure that the patient has access to the medication in a timely manner. Reliable follow-up is critical, and the patient must also be educated about signs or symptoms that should prompt a return to the emergency department. To facilitate access to these recommendations, the consensus panel also created 2 web-based "point-of-care tools."

Saddle Pulmonary Embolism: Demographics, Clinical Presentation, and Outcomes

Saddle pulmonary embolism is an uncommon type of venous thromboembolism that can lead to sudden hemodynamic collapse and death. Saddle pulmonary embolism can be difficult to recognize, and data on its presentation, clinical features, and associated complications are sparse. We sought to characterize patients with saddle pulmonary embolism.

DESIGN

The Montage software (Nuance, Burlington, MA) was used to identify patients to create a retrospective cohort study.

SETTING

Montefiore Medical Center from January 1, 2012, to December 31, 2018.

PATIENTS

All subjects diagnosed with saddle pulmonary embolism in above time period.

INTERVENTIONS

Charts were reviewed for demographics, diagnostics, laboratory data, presenting vital signs, inhospital mortality, 6-month survival, and prevalence of recurrent venous thromboembolism.

MEASUREMENTS AND MAIN RESULTS

About 120 patients with saddle pulmonary embolism were identified. Median age was 61 years and 57.5% were women. Events were provoked by a transient risk factor in 43.3%. On presentation, median mean arterial pressures were normal (93 mm Hg). Only five of 120 of patients (4.2%) presented with vitals concerning for massive pulmonary embolism. We found a 9.2% inhospital mortality; an additional 8.6% died within 6 months of discharge. Inhospital mortality was higher in women (11.6%), compared with men (3.9%), but this was not significant (p = 0.28). In 10 patients, both ventilation/perfusion scans and computed tomography pulmonary angiogram were performed. None of the ventilation/perfusion scans diagnosed saddle pulmonary embolism. Thrombus was visualized in the right heart in eight of 105 (7.6%), and this group had a higher inhospital mortality (37.5%). Recurrent venous thromboembolism occurred in 13 of 85 of survivors (15.3%).

CONCLUSIONS

Despite presenting without the accepted clinical criteria for massive pulmonary embolism, saddle pulmonary embolism has a very high inhospital mortality. Ventilation/perfusion scan is unable to diagnose saddle pulmonary embolism. Visualized right heart thrombi portend an even higher inhospital mortality.

Risk Stratification in Acute Pulmonary Embolism: The Latest Algorithms

Pulmonary embolism (PE) is a common clinical entity, which most clinicians will encounter. Appropriate risk stratification of patients is key to identify those who may benefit from reperfusion therapy. The first step in risk assessment should be the identification of hemodynamic instability and, if present, urgent patient consideration for systemic thrombolytics. In the absence of shock, there is a plethora of imaging studies, biochemical markers, and clinical scores that can be used to further assess the patients' short-term mortality risk. Integrated prediction models incorporate more information toward an individualized and precise mortality prediction. Additionally, bleeding risk scores should be utilized prior to initiation of anticoagulation and/or reperfusion therapy administration. Here, we review the latest algorithms for a comprehensive risk stratification of the patient with acute PE.

Saddle pulmonary embolism and clot in transit in COVID-19 infection: a case report of catastrophic venous thromboembolism

Background 

Coronavirus disease 2019 (COVID-19) is associated with a coagulopathy favouring thrombosis over bleeding that imparts a poor prognosis. Clot in transit (CIT) is considered a rare entity and the most severe form of venous thromboembolism (VTE), carrying a higher mortality than isolated pulmonary embolism (PE). The incidence of this phenomenon in patients with COVID-19 infection is unknown and likely under-recognized.

Case summary 

During the peak of the COVID-19 pandemic in New York City, a 70-year-old Hispanic female presented with syncope due to a saddle PE further complicated by a highly mobile CIT. Polymerase chain reaction was positive for COVID-19 infection, however, there was no evidence of lung parenchymal involvement or hyper-inflammation. Based on consensus from a multidisciplinary team, aspiration thrombectomy was attempted to treat this extreme case of VTE, however, the patient died during the procedure.

Discussion 

This case raises awareness to the most catastrophic form of VTE, presenting in an early phase of COVID-19 infection without the typical hyper-inflammation and severe lung injury associated with development of COVID-related coagulopathy. It also serves to inform on the critical role echocardiography has in the comprehensive evaluation and re-evaluation of hospitalized patients with COVID-19, and the importance of a multidisciplinary organized approach in clinical decision-making for this complex and poorly understood disease and its sequelae.